テスト。
(define A "abcde") (define B "1234") (define rev-list (lambda (list new-list) (cond ((null? list) new-list) (else (rev-list (cdr list) (cons (car list) new-list)))))) (define rev (lambda (str) (cond ((null? str) null) (else (list->string (rev-list (string->list str) '())))))) (rev (string-append (rev A) (rev B))) ;1234abcde